Re: [Qemu-devel] [PATCH V3] vl.c: fixed regression in machine error message

[Marcel Apfelbaum <marcel@redhat.com>]

On 02/08/2016 01:41 PM, Laszlo Ersek wrote:
> sorry, but:
>
> On 02/08/16 12:19, Marcel Apfelbaum wrote:
>> Commit e1ce0c3cb(vl.c: fix regression when reading machine type from config file)
>> fixed the error message when the machine type was supplied inside the
>> config file. However now the option name is not displayed correctly if
>> the error happens when the machine is specified at command line.
>>
>> Running
>>      ./x86_64-softmmu/qemu-system-x86_64 -M q35-1.5 -redir tcp:8022::22
>> will result in the error message:
>>      qemu-system-x86_64: -redir tcp:8022::22: unsupported machine type
>>      Use -machine help to list supported machines
>>
>> Fixed it by restoring the error location and also extracted the code
>> dealing with machine options into a separate function.
>>
>> Reported-by: Michael S. Tsirkin <mst@redhat.com>
>> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
>> ---
>>
>> v2 -> v3:
>>   - fixed commit message and called qemu_get_machine_opts only once. (thanks Laszlo)
>>
>> v1 -> v2:
>>   - Addressed Laszlo Ersek's comments:
>>     - no need to save the machine options location, is saved in opts
>>     - rename the extracted method to set_machine_options
>>     - added the bug reporter to the CC
>>
>>   - tested with and without the config file and the error message is now OK:
>>   config file:
>>      - qemu-system-x86_64:machine-bug.conf:3: unsupported machine type
>>   cli:
>>     - qemu-system-x86_64: -M q35-1.5: unsupported machine type
>>
>> Thanks,
>> Marcel
>>
>>   vl.c | 38 +++++++++++++++++++++++++++-----------
>>   1 file changed, 27 insertions(+), 11 deletions(-)
>>
>> diff --git a/vl.c b/vl.c
>> index c581e39..5873248 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -2748,6 +2748,32 @@ static const QEMUOption *lookup_opt(int argc, char **argv,
>>       return popt;
>>   }
>>
>> +static void set_machine_options(MachineClass **machine_class)
>> +{
>> +    const char *optarg;
>> +    QemuOpts *opts;
>> +    Location loc;
>> +
>> +    loc_push_none(&loc);
>> +
>> +    opts = qemu_get_machine_opts();
>> +    loc_push_none(&loc);
>> +    qemu_opts_loc_restore(opts);
>> +
>> +    optarg = qemu_opt_get(opts, "type");
>> +    if (optarg) {
>> +        *machine_class = machine_parse(optarg);
>> +    }
>> +
>> +    if (*machine_class == NULL) {
>> +        error_report("No machine specified, and there is no default");
>> +        error_printf("Use -machine help to list supported machines\n");
>> +        exit(1);
>> +    }
>> +
>> +    loc_pop(&loc);
>> +}
>
> You now have two pushes and one pop only.
>
> I don't know why I didn't notice this in v2. It's Monday. Sorry.

yep, definitely not my day. I was looking for a quick fix. I'll send another one...

Thanks,
Marcel

>
> Laszlo
>
>> +
>>   static int machine_set_property(void *opaque,
>>                                   const char *name, const char *value,
>>                                   Error **errp)
>> @@ -4028,17 +4054,7 @@ int main(int argc, char **argv, char **envp)
>>
>>       replay_configure(icount_opts);
>>
>> -    opts = qemu_get_machine_opts();
>> -    optarg = qemu_opt_get(opts, "type");
>> -    if (optarg) {
>> -        machine_class = machine_parse(optarg);
>> -    }
>> -
>> -    if (machine_class == NULL) {
>> -        error_report("No machine specified, and there is no default");
>> -        error_printf("Use -machine help to list supported machines\n");
>> -        exit(1);
>> -    }
>> +    set_machine_options(&machine_class);
>>
>>       set_memory_options(&ram_slots, &maxram_size, machine_class);
>>
>>
>